1. Technical Field
The present invention generally relates to processes for hydrogenating carbon monoxide, and more particularly relates to iron-based compositions for catalyzing such processes, and still more particularly to the manufacture of promoted iron-based catalysts.
2. Description of Related Art
The Fischer-Tropsch process is a well known catalyzed reaction in which carbon monoxide and hydrogen are converted into various forms of hydrocarbons. Catalysts for the reaction are commonly based on iron, sometimes using a precipitated iron-based catalyst that also contains some type of promoter to improve catalyst stability or to affect the properties of the hydrocarbons produced.
U.S. Pat. No. 5,504,118 describes Fischer-Tropsch reaction schemes using certain iron catalysts promoted with potassium and copper in a slurry reactor to produce hydrocarbon products having more than five carbon atoms, water, and alcohols.
German Patent No. 763864 describes certain methods of making iron catalysts for production of hydrocarbons from carbon monoxide and hydrogen under normal or increased pressure (5-50 atm). The catalysts contain bi- and trivalent iron salts and up to 0.5% copper, and are made by heating and precipitating the solutions.
There is continuing interest in the development of iron-based catalysts for catalyzing the hydrogenation of carbon monoxide to form hydrocarbons.